Thermostatic circuit closer



June .5, 1923. 457,939

J. C. F. ROQUETTE THERMOSTATIC CIRCUIT CLOSER Filed June 17, 1921 2Sheets-Sheet l .Tigi.

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J. C. F. ROQUETTE THERMOSTATIC CIRCUIT CLOSER Filed June 17, 1921 2Sheets-Sheet 2 I Fig.5;

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Patented June 5, 1923.

UNITED STATES PATENT @FFICE.

JOSE CORDEIBO FERREIRA. ROQUETTE, OF PARIS, FRANCE, ASSIGNOR TO MANOELDE ORTIGAO BURNAY, (3F PARTS, lEtANCE.

THERMOSTATIC CIRCUIT CLOSER.

Application filed June 17, 1921.

To all whom it may concern:

Be it known that I, J osii Connnrno Fun- REIRA Ro UEm, citizen of theRepublic of Portugal, residing at 139 Boulevard P- reire, Paris, France,have invented certain new and useful Improvement in Thermostatic CircuitClosers, of which the following is a specification, reference being hadtherein to the accompanying drawing.

Fire alarm signals have been heretofore proposed, in which the airexpanding under the action of the heat causes closing of an electriccircuit connected to the signal apparatus proper, such as an audiblealarm.

The present invention relates to an ar-- rangement of the foregoingtype, and is characterized by the fact that the dilatable chambercommunicating with the air expansion chamber is provided on itsextensible wall with an air escape orifice opposite a regulating member,such as a pointed screw, and opening freely to atmosphere, theconstruction being such that the orifice closes progressively when theextensible walls of the dilatable chamber approach the regulating memberunder the action of the increased pressure of the heated air.

A representative embodiment of the invention is illustrated by the wayof example on the accompanying drawing, in which Fig. 1 is a verticalsection of the apparatus,

Fig. 2 is a plan, and

Fig. 3 is a horizontal section on the line 3-3 of Fig. 1.

Fig. 4 is a vertical section on a larger scale showing the air vent.

Fig. 5 is a vertical section. also on the larger scale, showing theattachment of the electric terminal to one of the supports of theapparatus.

The apparatus consists of an air expansion chamber, a dilatable chamberand a frame supporting these two chambers.

The air expansion chamber 1 is provided between a sheet metal cylinder 2and a sheet metal cylinder 3, having large corrugations 4; thesecylinders being with advantage built up of very thin good heatconducting material yet having as small a coefficient of expansion aspossible.

The chamber 1 i closed on top by an annular disc 5. The cylinder 2 isclosed at the Serial No. 478,336.

base by a circular bottom 6 and the cylinder 3, having the corrugatedperiphery, by an annular disc 7, providing between them a free space 3,freely communicating on the one hand with the air expansion chamber 1and on the other hand, by a passage 9, with the dilatable chamber 10.

The dilatable chamber 10 has a base 11 constituted by a corrugatedyielding diaphragm, like the diaphragms of the chambers of aneroidbarometers, and provided with an air vent 12.

This air vent is constituted as follows: A socket 13 (Fig. 4) is securedto the base 11 of the dilatable chamber and communicates therewith by anorifice 14:. A washer 15 perforated centrally is screwed on the socket13. A choking substance of any kind, cotton wool for instance, islocated at 16 within the socket 13.

A pointed adjustable screw 18, mounted on the frame of the apparatus,controls the aperture of the washer 15.

A ring 420 of insulating material is interposed between the pointedscrew 18 and the plate 26 and insulates these elements one from theother. The conducting wire is secured between the ring 40 and the plate26.

The frame of the apparatus is built up of uprights 25, four for example,interconnected on the one end by the annular upper late 5, and on theother end by a circular lower plate 26.

On the circular plate 26 are mounted insulated supporting pillars 27, onwhich rests the base of the air expansion chamber; one of these pillarscarries a blade spring 28, the free end of which is bent towards thecorrugated diaphragm 11 of the dilatable chamber 10; this spring canencounter an electric contact 29, mounted on the plate 26.

The plate 26 also carries electric terminals 30 and the pointed screw 18which controls the aperture of the washer 15.

Each terminal 30 is constituted for example (Fig. 5) by a metal nut 32,screwed on a screwthreaded extension 33 of an upright 25, such metalsleeve and extension being insulated by an insulating socket 34 from theconductive plate 26.

A kind of dome 35 envelopes the lower portion of the apparatus. A. widemesh screen 36 may moreover be secured to the .lows: It a fire breaksout the heat waves produced come into contact with both the externalcorrugated surface of: the cylinder 3 and with the internal surface ofthe cylinder 2, which is freely open at the top. The cylinders 2 and 3,of good heat conducting material, become heated, and likewise the aircontained in the chamber 1. Such air expands, its pressure increases, asthe pointed Screw 18 controlling the aperture of the washer 15, and thepacked mass of choking material, cotton wool for example, oppose theescape of the air. Under the action oi this increase of pressure of theair, the yielding diaphragm ll of the dilatable chamber 10, dilates,comes into contact with the blade spring 28 and thrusts The dilation ofthe dilatable chamber 10 results also in the washer l5 approaching thepointed screw 18 and in consequence, reducing more and more the area otthe air vent in such washer, the internal air pressure of the chamber 1then increases and the blade spring 28 becomes more and more downwardlybent and finally encounters with the electric contact 29.

Instead of actuating an electric bell, the

completed electric circuit may open or initiate the opening of thecontrol cock of a fire quenching sprinkler system, or the like.

Normal gradual heating of the apartment in which the apparatus isituated, has no effect thereon, the expanding air gradually escapesthrough the vent without dilating the chamber 10.

Claims:

1. In an alarm apparatus of the character described, the combination ofa dilat-able chamber having an extensible wall provided with an airescape orifice opening to atmosphere, a regulating member mounted on theframe of the apparatus and arranged opposite said orifice, meanscontrolled. by the diiatable chamber when the latter expands to close anelectric circuit connected to the alarm proper, and an air expansionchamber communi *ating with the dilatable chamber.

2. A fire alarm apparatus a claimed in claim 1 characterized by twocylindrical walls arranged one within the other, the exteriorcylindrical wall presenting large undulations and being closed at itslower part by a plate, the interior cylindrical wall be ing closed atits lower part by a plate and freely open at its upper part, and anannular plate closing the upper part of the free space between the twowalls, said space constituting the air expansion chamber andcommunicating with the dilatable chamber.

In testimony whereof I have hereunto aflixed my signature.

JOSE CORDEIRO FERREIRA ROQUETTE.

